Apparatus for variable speed control



1940' D. E. LEWELLEN ET AL 2,212,194-

APPARATUS FOR VARIABLE SPEED CONTROL Filed Aug. 10, 1937 3 Sheets-Sheet 1 HIGH QPEED II V/l/ ////l A arU Jrwm DARCYELEWELLEN.

MMo/vs F. LEWELLEN, .5Y

Aug. 20, 1940.

D. E. LEWELLEN ET AL APPARATUS FOR VARIABLE SPEED CONTROL Filed Aug. 10, 1937 3 Sheets-Sheet 2 J-rvuendo'os DARCY fuzEwELLE'N .EMMQNS FILEWCLLEN,

MJM) allow/ways Aug. 21'); 1 940. D. g. LEWELLEN ET AL 22l2,194

APPARATUS FOR VARIABLE SPEED CONTROL Fi led Aug. 10, 1937 s Sheets-Sheet 3 DARCY BI-EWELLEN, m .EMMONS F-IEWELLEN,

Patented Aug. 20, 1940 UNITED STATES membrane f APPARATUS FOR VARIABLE SPEED-L "CONTROL v Darcy E. Lewellen and Emmons .Lewellen,

2 Columbus, Ind. i L

Application August 10, 1937, Serial No. 158,363

'7 Claims. (01. 74 23f0.17)

will be ruptured. It is further necessary to acthe minimum and maximum speeds it may be set torun at predetermined intermediate high ,speeds. The advantage of this arrangement in rolling of metal sheets and the like is that the rolls can be started for the initial rolling action until the inertia of the metal is overcome and they. can be then increased in their speed gradually up to predetermined limits so that the speed of the rollsis never greater than that which the strength of the metal will stand without rupture. It is an object of this invention to provide power driven rolls with a variable speed transmission interposed between the prime mover and the rolls, capable of an infinite number of speeds with a pilot motor adapted to adjust the variable speed mechanism, and with a suitable electrical control for said pilot motor which can be operated to bring the adjustment of the variable 1 speed transmission to a predetermined point, at which point a control switch renders the pilot motor inoperative and the transmission continues 'to'operate at the predetermined speed thus set.

It is a further object in this connection to pro vide means for temporarily manually controlling v the intermediate movements of the pilot motor or of :setting the electrical mechanism for operat- 'ingthe pilot motor to bring about a predetermined speed without further manual attention.

Referring to the drawings,

mechanical and electrical arrangements com prising this invention.

Figure 2 is a side elevation of the supply takevup and rollingqrolls for .the metal sheet an'dthe I tor.

as indicated by the arrows.

[Figure 1 is a diagrammatic view showing the variable speed transmissionwith the driving mo- Figure 3 is a top plan view of the variable speed mechanism. Figure 4 is a section on the line 4--.4 of Figure 1 showing the adjustable nature of the controlling lever operating the control speed setting switch. Referring to the drawings in detail, amain driving motor I is connected to the incoming power lines 2, 3 and 4 through the main switch r1113 5. This motor drives through the belt 6, the pulley l on the'driving shaft 8 of a variable speed transmission generally designated 9. Mounted on this shaft are a pair of discs H) which can be moved inwardly and outwardly by the arms I l in the usual manner to vary the speed of the driven shaft l2. These arms are" pivoted at l3.

At their other ends they are connected to the driven discs H! which are simultaneously moved inwardly and outwardly oppositely to the move- .20 'ment of the discs 10.

Between these discs is a power transmitting belt l5.. The arms I l are actuatedinwardly and outwardly by the screw l'6 which is threaded through blocks l1 andl8 on the ends of the levers -II.25 This screw is rotated in opposite directions through the gear box l9 by the pilot motor 20.

The driven shaft lzis connected by either gears or a chain to the rolls to be driven. In this instance is shown a chain 2| mounted on suitablew sprockets 22 and 23 for driving the roll 2 .811- perimposed above this roll is another roll 25. These rolls are interconnected by gears Hand 27. The metal sheet 28 passes between the rolls,

Returning to the variable speedltransmission, it will be observed that there is mounted on one side thereof a switch arm 29 that has a roller3l) on one end thereof. This switch arm is adapted to open and close the contacts 3! and32. It'isrg actuated by the adjustable control bar 33 which is guided at one end by the slotted bracket 34 and which is connected at the other end 35 by the bar 31 to the lever H. The bar 31 has graduations 38,and superimposed upon this bar is the bar 33 which has a slot 39 through which project the set screws d ll for adjustingthe overall distance between support 35 and the end of the bar. This bar is provided with a cam shaped recess 4!, the outer end of which engages the'50 roller 30 to open and close the switch. This switch is adapted to control the operation, under certain conditions, of the pilot motor 2|] as hereinafter described. I g v There is also associatedwith this transmisopening the switch 43. Likewise the high speed lever 44 controlling the switch 45 maybe similarly actuated.

Electrical control mechanism The purpose of this electrical control mechanism is to close an electrical circuit to actuate the pilot motor 20 so that it will continue to operate in either direction selected to .bring the transmission gradually to a predetermined setting for high or low speed. A part of this circuit is arranged so'that by merely holding in the so-called slow or fast buttons on the switchboard, the pilot motor willcontinue to operate aszlong. as these buttonsare. held -in;-limited by the action of the limit switches 42 and 44.

i' There; are izotherf: buttons which likewise control the mechanism but only haveto-be pressed 5 .into"closin'gposition and then can lbe released,

as thegelectri-oal setting mechanism and holding mechanism :will' continue to function automati- ,::.ca1ly thereafter. Thislatter arrangement oper- "atesras'follows;

Automatic high speed The 'automatic-.highspeed button 46 is pushed I in toengagecthe terminals 4? and 48.. In doing so it closes'the.followingcircuit. The wire -49 is connected to-the solenoid 50 :ofthe fast hold- -.down switch 5! which; is. thusclosed. Thewire 152 leads-to:theterminal 1320f the control speed setting switch -29. -The-otherside of this switch "at .3I is connectedby the wire 53 to-the high speed -solenoidsswitch 54 which closes the switch 55.

This results in bringing the threeephase lines 56,

'51. and 58 of the pilot-motor 20 in circuitinsuch armanner that the vmotoriil will move the-levers l l togetherin-such amanner asto move the discs Q IOI-itogethenthereby. increasing thespeedof the ro s. l

Thus,- andrin particular, when. the normally open high :speed .push'- button switch 46 is closed; the circuit. is closedrfrom the power line .5 4 to.,and-.throughthe-contacts Stand 61 of the normally closed stop push button switch 6 5, thence :to and through the conta'ctsfl4l-.rand.48 of the above-mentioned: and now closed push button --switch =.46,- themes-through the linew49 to and through the solenoid coil.5fl through the line 52 .and thrOughrthe contacts SI-rand 32-associated with the switch -.2 9.,- thence through-the-lines 53 "and-Slate and through the contacts 45 and thence through the line-6ll to the power line 3, completmowing the circuit.

rif the speed should exceed a predetermined .7 amount, the highspeedvswitchlever' 44 would be ,actuated-zand the pilot-motor stopped. The same is. true of-the operation oi the low; speed lever 42. -.:'I"here--are:also brought'in circuitthe wires 62 and 6 3 which include a signal light :64 that is il- -luminated': when the :machineis running at high.

actuated.

speed. If it is desired to stop the pilot motor for any reason, the push button which is normally closed across the terminals 66 and 51 may be operated to open the circuit and stop the pilot motor at any time. 5

Low speed automatic control The low speed'button 68 operates in a similar manner in that it brings'in circuit, by bridging the terminals es and m, the slow hold-down 10 solenoid ll of the slow hold-down switch 12 determined low speed.

The manual hold-down slow speed button '11 is adapted to operate, asindicated, the slow speed switch solenoid l4 and switch 75 without bringing in circuit the hold-down switch and its solenoid H and switch 12. -When thisbutton is released manually, then the pilot motor is no longer Thus, and in particular, when the normally open slow push button switch I! is closed, the circuit is closed from the power line 4 to and through'the contacts 66 and 61 of the normaly closed stop push button switch 65, thence through the. contacts of the above-mentioned and now closed push button switch 11, thence through the solenoid: coil as and the line 59 to and through the contacts 43 and line tothe power line 3,

noid- 5t and the switch 5!.

'Thus,'and inparticular, when the normally open fast -pushbutton switch-.liiis closed the circuit is.- closed from the. power line 4 to and through the contacts Stand 51 of the normallyil45 closed stoppush button switch iii-thence through the. contactstofr-the'above-mentioned and now closed push button tswitch l6, thence through the solenoid coil 54, theline 6i and the contacts .45, andthenc'e through theline .60 tothe power line 960 3, completing the circuit.

.This electrical control therefore consists of the following: a pilot motor that can be Operated in either direction for setting the variable speed transmission to a predetermined high or lowo2i5 speed. When once started by the high speed or low speed switch, or operated with the hold-down switch if that is used, the pilot motor will continue to operatein the direction in which it is set to move until it is stopped by the movemento50 of the transmission being so adjusted to the pilot motor which opens the switch 29, 42 or 44. It will continue to operate at the speed so. set. It is apparent that any number of such adjustments may be effected as desired and that only onez1fi5 typical form has been indicated here.

One of the particular advantages of this invention is that the control does notdepend upon anycontact with the sheet being treated.

Another important advantage is that the rolls-i170 may be brought up to speed and the sheet being treated brought up to speed to overcome the inertia of the latter andto bring both the rolls and the sheet-into a harmonious speed relationoshipiatsslowspeed; that thereafter when the pilot motor is-put into operation, the transmisthe metaland with the minimum of shutfdowns sion is gradually increasedin its speed relationships so that the rolls are gradually 'speededup fof moving the'metal betweenthe rolls at such a speed to overcome the inertia of the metal without rupturing the sheet being handled and by this gradual means the sheet can be handled at much higher speeds'than heretofore thought possible, and with improved results of finish, etc.

The maximum speed can be set according to the setting of the control lever as the graduations 38 indicate in termspf speed setting desired. The control lever then stops further adj'usting the, movement of the transmission by opening the pilot motor circuit and the machine will operate at the speed to which it has thus been brought up gradually. Likewise it can be controlledby varying the speed by using the fast and slowpush buttons. Intermediate positions can be accomplished by holding in the fast or slow switch buttons 16; or H so the exact speed ofthe adjustment is always within the control of the operator, thus limiting the effect of shutdowns and the like.

It has been found possible with this invention to accomplish rolling speeds heretofore not found possible.

Metal rolling One of the typical uses of this invention is in connection with metal rolling such as the production and thickness of metal sheets, the surfaces of which must be burnished in order to make them into foil. The sheet 28 is fed from a supply roll 28a and is taken up on the take-up,

roll 28b. The inertia of this sheet and its associated supply roll must be overcome in starting without rupturing the sheet. The rolls are therefore started up at a predetermined relatively low speed which is insuflicient to rupture the sheet but which will gradually overcome the inertia of its mass so that it will satisfactorily pass between the rolls. Heretofore this has been thought to be the maximum speed of which the sheet would be capable without injury. It was also thought that the rolls would not suitably burnish the sheets and that the bearings of the rolls would not stand higher speeds in view of the pressures employed. These speeds were about 140 feet per minute. However, by this invention it is possible to increase these speeds up to 300 feet per minute and the total possible maximum speed has not yet been completely explored, as these speeds are constantly being increased by the use of this invention.

By this invention, after this initial speed has been accomplished by the original setting of the speed transmission, the speed is gradually increased by adjusting the transmission through the pilot motor 20. This speed progressively increases the speed of the sheet as the speed of the rolls is increased. This continues untilthe maximum speed selected has been accomplishedwhen the pilot motor is rendered inoperative. The speed is increased gradually always beneath the rupturing speed for the metal, but progresdue to the rupturing of the sheet. a

-The method ofdoing this comprises the step without rupturing the metal sheet and the further step of increasing the speed of the "metal sheet and the rolls when this inertia has been overcome, at such a rate that the sheet is'never ruptured but the speed of the sheet is increased up to, but just under, that'speed which would bring about a rupture. This requires the automatic control features of this invention.

It will be understood that we desire to comprehend within our invention such' modifications as come within the scope of the claims and the invention.

Having thus fully described our invention what desire to secure by Letters ment in either direction, and means for adjusting the time in the operation of the machine when the limit switch operates.

2. The combination, with a variable speed transmission adapted to progressively increase or decrease the speed of a driven member, of a pilot motor adapted to move the parts of said transmission to adjust its speed, a limit switch for rendering said motor inoperative upon the accomplishment of a predetermined movement in a given direction and adjustable stop means carried by a part of said transmission for engaging said limit switch to adjust the time at which the limit switch is operated.

3'. The combination, with a variable speed transmission adapted to progressively increase or decrease the speed of a driven member, of a pilot motor adapted to move the parts of said transmission to adjust its speed, a limit switch for rendering said motor inoperative upon the accomplishment of a predetermined movement in a given direction, adjustable stop means carried by a part of said transmission for engaging said limit switch to adjust the time at which the limit switch is operated, and means actuated by the adjustment of said transmission when the transmission exceeds a predetermined maximum or minimum speed for rendering said pilot motor inoperative.

4. The combination, with a variable speed transmission driven by a prime moving motor and adapted to progressively increase or decrease the speed of a driven member, of a pilot motor adapted to move the parts of said transmission to adjust its speed, a limit switch for rendering said motor inoperative upon the accomplishment of a predetermined movement in a given direction, adjustable stop means carried by a part of said transmission for engaging said limit switch to adjust the time at which the limit switch is operated, means actuated by the adjustment of said stop means when the transmission exceeds a predetermined maximum speed for rendering said adjusting motor inoperative and manually operated means for rendering said adjusting motor inoperative withoutrendering the prime moving motor inoperative.

5. The combination, with a variable speed 5 transmission, of a pilot motor for adjusting said transmission, a control bar; mounted on the adjusted mechanism thereof; a speed setting switch actuated thereby for stopping the pilot motor, means for selecting the'direction of movement of the pilot motor and for connecting it into circuit,

-motor adapted to actuate said lever system in Y opposite; directions, an-adjustable control bar associated with said lever system, a speed setting switch actuated thereby in-cirouit with said motor, and a maximum and minimum speed switch adapted to be actuated by said lever system for controlling the stopping'o-f said pilot motor, said speed setting switch being actuated by said control bar, at a predetermined inter-@ mediate speed between said maximum and mini- 'mum speeds.

7. The combination, with a variable speed transmission adapted to progressively increase .or decrease the speed of a driven machine, of a,

pilotmoto-r adapted to move the parts of said transmission to adjust its speed, limit switches for. rendering said motor inoperative and thus prevent the transmission parts moving beyond predetermined limits, an adjustable stop, and a,-

switch actuated by engagement with said adjustable stop for stopping operation of said pilot motor at any predetermined intermediate speed.

DARCY E. LEWELLEN. EMMONS F. LEWELLEN. 

